Collapsible joist-boring machine



Rv. H. HENDERSON'. QOLLAPSIBLE JOIST BORING MCHINEI APPLICATION FILED MAR. I3, |920.

Patented. Aug. 22,

' at the point O overdap;

or standard sections in boring bit, and-'an idler pulley UNITED Sura i ROBERT HALSEY aanpassen, or EAST onsneisgiiriw JERSEY.)

COLLAPSBL'E {ICIST-BORING MACHINE.

Specification of Letters Patent. y ilgnigd Aug, 22,. 419522...v

i Application led March 13, 1920. Serial No. 365,413., i

`- vented certain new and useful improvements in Collapsible Joist-Boring Machines; and I do hereby declare the tollowing to be a full, clear, and exact description of the invention, such as will en;v

able others skilled in the art to which 'it appertains to make and use the same, reference being had ,to the accompanying drawings, and to characters of reference `marked thereon, which form a part of'this specification.

The present invention relates, generally,

to improvements in collapsible joist boring machines provided with a chain Adriven ro-r` tatable head at its upper end carrying a chuck for connecting therewith a suitable adjacent to its lower end for guiding the driving chain; and the invention has reference, more particularly, to a novel clamp joint forinterlocking the telescopically associated 'column extended 'operative relation so as to iirmly hold the same against accidental collapse, and-so as to aline the same to support the driving chain between the head and said idler pulley in true running alinement at proper, tension.

In such telescopically collapsible joist boring machines it is essential that the locking joints between the tubular column or standard sectionsv serve to firmly hold said sections against accidental collapse, when eX- tended, at a iixed predeterminedpoint and in correctalinement so that the' endless driving' chain may run freely and true between the head sprocket' and the guiding idler pulley; and, furthermore, saidv joints must be capable of being frequently tightened and released without causing injury to the sections themselves, such as distortions or scorings of the overlapping surfaces of `the sec tions tending to interfere with or obstruct the mutual sliding relation of the saine,lso that said sections are maintained. in a' condition rendering repeated telescopic collapse ot the same freely and easily accomplished.'

Heretoifore two styles of joints have been generally used;v a strap clamp, passing around the joint rand adapted to shrink the larger tubular section in hugging or gripping relation tothe smaller tubular section in some instances HALSEY HEN- s resistir 4orsisie.A U

two or three ot such strap clamps are used vat a single joint in an effort' to render .thelatter strong enough ;.the other torinof clampv consists of an ordinary jam.screwfpassk'ii'iigr through a threaded boss connected with the largertubular section,and dependingijor I i its holding power upon the'poiiit' or cupwend ot' the j amy screw biting into the outside surtace ofthe smaller ,tubular section. vB

`oth of the types ot clamps tend to either distortv or score the smaller tubular section with thel il result that smoothl and easy sliding relations of `the sections. is interfered with'. Neither of said' type oieiclarnps, in themselves, 4furnish any y" j n n j I guide or means assuring that the' respective sections will be locle'd atv a eredetermined pointleach time so thata' proper ltension Lvand true alinementw'ot ther driving chain'of Athe ineehanisin'y is also. assure/d each time the mechanismis set up,`and

in tact the operatonwhen. dependentupon fi 'such clamps, must rely upon hiseyeto alinel the chain and must guess at the tension pro.- f

@onsequently it ru'n true or duced.

the chain does not is" too tiglit',`botli the chainl and jected to wear, as is also the idle'rypulley, and .since a chain that runs at proper tensiomjin other i undue strains fand j unnecessaryf` words with proper `degreer of freedom, will j easily boreholes underga minimum of power applicatioinltherefore a `chain Awhich isvtool tight requiresv unnecessary' effort" to be uexper-" cised by the'oper'ator.; F rtiierinore', .j when clamps'oi2 thekind abovementioned are ern-L ,L t

are likely to 'accidentally i curelyagainst accidental collapse, lwhereby theV objectionable 4tea-tur use ofl'old st leclampg .above pointed-(mt are substantially eliminated.

accon'i'panying drawings, iny which ,f-

es. incident ,the v v j i054 Theinve'ntion is kclearly illustrated ,mythe Figure'jl is aside elevationot acollapsible joistboring machinein extended operative position, j j ing to andpembodying the pifinciples yoiffmvy present invention. j 'V l the same beingmade accord-1,1110

ioo predetermined "relative positions `and se-l Y lar column or standard y chuck-sleeve 9, made in two longitudinal sections,

Figure 2 is a similar view of said joist boring machine in collapsed position, the drivingl chain thereof being removed.

.Figure 3 is a vertical longitudinal section of said collapsible joist boring machine in extended operative position, said view being drawn on an enlarged scale, and portions thereof being broken away to reduce the length thereof to permit illustration of all its essential parts.

Figure 4 is a detail longitudinal section of a slightly modified form of the novel clamp joint.

Similar characters of reference are einployed in all of the hereinabove described views, to indicate corresponding parts.

Referring now to said drawings, the reference character 1 indicates an upper tubusection, to the upper end of which is fixed a 'l' head 2 provided with ball anti-friction bearings 3i. Journaled in said bearings 3 is horizontal hollow shaft 4 provided at one exterior end with a sprocket wheel '5 and a bearing face 6 which rides against one bearings. The opposite end of hollow shaft is eXter'iorly threaded, and a bearing face 7 is engaged over the same and secured in operative relation to the opposite set of said ball bearings by means of a nut 8 which screws upon said threaded shaft end. Arranged within said hollow shaft is a split semi-cylindrical and adapted to conform to and embrace the butt 10 of a boring bit 11 which projects outwardly from the end of said shaft beyond the sprocket wheel 5. Said chuck sleeve 9 is secured against withdrawal from said hollow shaft, and at the same time connected therewith to vreceive therefrom and impart to said boring bit 11 operative rotary motion, by means of a transverse coupling pin or key 12. Running over said sprocket wheel 5 is an endless link belt or drive chain 13.

The reference-character 14 indicates a lower tubular column or standard. section, which is slidably received within the lower end of said column or standard section 1 so as to telescope thereinto. The lower extremityA of said columnvor standard section 14 is provided with. an eXteriorly disposed iitting 15 threaded thereto, and provided at its free i end with va portion 16 of reduceddiameter.

Said fitting 15 is provided with a laterally projecting` internally threaded boss 1.7. Telescopically slidable into the lower end of said column or standard section 14. through the reduced portion 16 of said fitting 15, is an extensible leg or foot piece18. The reference-character- 19 indicates a set screw which screws into saidthreaded opening of said boss 17, so as to engage and lock said leg or foot piece 18 in any desired adjusted extended position relative to said column or set of said ball,

standard section 14. Said set screw 19 is of a length suiimicient to project far enough outwardly from said-boss 17-to provide a journal or bearing for a fianged idler pulley 20, whichv is mounted thereon for free rotation. rl'he lower loop or end of said link belt or chain 13 runs over and is guided by said flanged idler pulley 20.

The novel arrangement of clamp joint for interlocking said respective column oristan# dard sections 1 and 14 together in operative extension, and which is adapted to i'irmly secure the same against accidental collapse when the machine is in use, and which further serves to automatically aline the sprocketwheel carried by the upper section with the idler pulley carried by-the lower section7 and at the same time predetermines the operative spaced relation of said idler pulley said sprocketjwheel so that the link belt or driving chain running over the same is assured of being operatively mounted to run under the desired tension,` as well as in true running alinement, comprises a embrace the lower extremsection 1, by meoans of a rivet 22, or any other suitable fastening means. Said sleeve 21 is provided with a laterally projecting boss 23 having an internally screw-threaded opening 24, an opening25 registered with the said threaded opening 24 being provided in the wall of said section 1. The wall of said lower tubular section 14 is provided, at one side adja-` cent to its upperextremity, with an opening or eye 26, which, when said lower section 14 is moved to outwardly extended operative relation to said upper section 1, is brought into alinement with the of said boss 23. A lock or thumb. screw 27 screws through said threaded opening 24 of said boss 23, and when said lower section 14 is extended to operative position and the opening or eye 26 brought into alinement with said lock or thumb screw 27, the latter maybe screwed inwardly to pass its extremsleeve 21 fined to ityk of said upper ity through the said opening or. eye r26, so

that its said extremity may be movedinto binding or holdingrelation to said lower section 14 by engaging' the inner surface of thewall of the latter at a point diametrically opposite said opening .or eye 26, thus locking the two sections 1 and 14 together in operative extended relation., extremity of said lock or thumb screw does not engage the outery surface of the lower section 14,-which meets and slides against the inner surface of the upper section ,1, therek ensues no scoring, distortionor other injury to said sliding surface likely to interfere with or obstruct the easy telescopic collapsing or extending operations of the mutually related upper and lower sections 1 and 14. Furthermore, even though the lock or thumb screw 27 becomes accidentally threaded opening24 Since the biting v assure the proper loosened, collapse of the operatively extended sections does not iolloiv, since the shank of the screw 2T in passing through the eye or opening 26 of the lower section, so engages the latter as to prevent accidental dropping or collapsing or' the upper section, and no collapsing oi said sections can takefwplace until the said screw 27 is entirely Withdrawn.

out orP the opening or eye 26. Since the opening or eye 26 is carefully positioned in the manufacture or the machine so as to predetermine both the alineinent oi the sections l and la to properly 'opposev the sprocket Wheel 5 and idler pulley 20, as Well as to longitudinal spacing or the same whereby the tree runningtension of the drive chainis secured, it ollovvs'that the passing of the screw 2"( therethrough to operative binding or llocking position, likewise automatically alines the drive chain at proper running tension, with all consequent advantages above mentioned. j i Adjustments tendingto vary t ie operative elevation or the boring bit head from the floor are madeby regulating the 'projection of the leg or toot piece 18 from the lower end of the lower section lll, once the main column or standard sections l and le are locked in operative extended relation.

Referring now to Figure l l have shown a sligthly modified arrangement and construction of clamp joint, which still embodies the general principles or my present invention. ln this construction l provide the sleeve 21 having the lateral boss 23, but instead of threading the opening or said boss l provide a clearance opening 28.- 'lhe adjoining end or the lovver section le is provided With a threaded aligning opening or eye 29 With which the threaded shank or said lock screw 27 may be engaged after passing through said clearance opening 28.

vcarrying a rotatable ltvvill be apparent poses and obtain all the advantages already pointed outk in connection scribedv construction. j j p lt Wilkocourse, he understood that tWo or more column or standard seetionspvvith requisite novel interlocking clamp. joints, maybe employed.

Having thus vdescribed my inventionin". zv

detail, l claim ze A ln a joist boring machine, a collapsible 'y standard comprising a plurality or telescop-l ically associated tubular sections of circular cross sectional shape, the upper section boring bit head having al driving sprocket, they lower section 'carrying an 'idler pulley, van endless drive chain running over and between said sprocket and idler pulley, andv means for interlocking said sections in predetermined extended relation v whereby said sprocket and idler pulley are vertically alined in proper spaced relation to establish the straight 'running of said drive'chain at proper tension, `said means comprising a vthumb threaded relation to the end oi: one section, the engaging end ofthe adjoining section having an aligningeye in its Wall through Awhich the biting-'end of said thumb screvv is passed to binding engagement with the Iopposite innersuriface or saidsection, to torce 'said section in clamped relation to the other section and securely held against vvabhling.

lin testimony, that l claim the invention set 'forth above l have hereunto set my hand this 11th day of March, 1920.

narrar HALSEY nrnnrrson Witnesses:

` GEORGE D. RICHARDS,

BARBARA' W. Soir'rnmn.

that the clamp joint thus 'modiiied will, nevertheless serve all the purj with the' first deeo i screvv in transverse 

